1.1 Introduction to the Practice of Statistics
1 Define Statistics and Statistical Thinking
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
1) What is statistics?
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
2) Which of the following is not true of statistics?
A) Statistics is used to answer questions with 100% certainty.
B) Statistics involves collecting and summarizing data.
C) Statistics can be used to organize and analyze information.
D) Statistics is used to draw conclusions using data.
2 Understand the Process of Statistics
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
1) A survey of 1348 American households found that 48% of the households own a computer. Identify the
population, the sample, and the individuals in the study.
2) A survey of 1388 American households found that 55% of the households own at least two cars. Identify the
population, the sample, and the individuals in the study.
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
3) Parking at a large university has become a very big problem. University administrators are interested in
determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An
administrator inconspicuously followed 210 students and carefully recorded their parking times. Identify the
population of interest to the university administration.
A) the parking times of the entire set of students that park at the university
B) the parking times of the 210 students from whom the data were collected
C) the entire set of faculty, staff, and students that park at the university
D) the students that park at the university between 9 and 10 AM on Wednesdays
4) A manufacturer of cellular phones has decided that an assembly line is operating satisfactorily if less than 0.0
5% of the phones produced per day are defective. To check the quality of a dayʹs production, the company
decides to randomly sample 60 phones from a dayʹs production to test for defects. Define the population of
interest to the manufacturer.
A) all the phones produced during the day in question
B) the 60 phones sampled and tested
C) the 60 responses: defective or not defective
D) the 0.05% of the phones that are defective
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, 5) A study published in 1990 attempted to estimate the proportion of Florida residents who were willing to spend
more tax dollars on protecting the Florida beaches from environmental disasters. Forty-eight hundred Florida
residents were surveyed. Which of the following is the population used in the study?
A) all Florida residents
B) the 4800 Florida residents surveyed
C) the Florida residents who were willing to spend more tax dollars on protecting the beaches from
environmental disasters
D) all Florida residents who lived along the beaches
6) Parking at a large university has become a very big problem. University administrators are interested in
determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An
administrator inconspicuously followed 130 students and carefully recorded their parking times. Identify the
sample of interest to the university administration.
A) parking times of the 130 students B) parking time of a student
C) location of the parking spot D) type of car (import or domestic)
7) The legal profession conducted a study to determine the percentage of cardiologists who had been sued for
malpractice in the last three years. The sample was randomly chosen from a national directory of doctors.
Identify the individuals in the study.
A) each cardiologist selected from the directory
B) the responses: have been sued/have not been sued for malpractice in the last three years
C) the doctorʹs area of expertise (i.e., cardiology, pediatrics, etc.)
D) all cardiologists in the directory
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
8) Administrators at a large university want to know the average debt incurred by their graduates. Surveys were
mailed to 260 graduating seniors asking them to report their total student loan debt. Identify the population,
sample, and individuals in the study.
9) A study was conducted to determine if listening to heavy metal music affects critical thinking. To test the claim,
102 subjects were randomly assigned to two groups. Both groups were administered a basic math skills exam.
The first group took the exam while heavy metal music was piped into the exam room, while the second group
took the exam in a silent room. The mean exam score for the first group was 78, and the mean exam score for
the second group was 87. The researchers concluded that heavy metal music negatively affects critical thinking.
Identify (a) the research objective, (b) the sample, (c) the descriptive statistics, and (d) the conclusions made in
the study.
10) A telephone poll asked 1349 registered voters ʺWould you vote for the current vice president if he ran for
president?ʺ Of these 1349 respondents, 32% would vote for the current vice president if he ran for president.
The administrators of the study concluded that 32% of all registered voters would vote for the current vice
president if he ran for president. Identify (a) the research objective, (b) the sample, (c) the descriptive statistics,
and (d) the conclusions made in the study.
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,MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
11) Which branch of statistics deals with the organization and summarization of collected information?
A) Descriptive statistics B) Inferential statistics
C) Survey design D) Computational statistics
3 Distinguish Between Qualitative and Quantitative Variables
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Classify the colors of automobiles on a used car lot as qualitative data or quantitative data.
A) qualitative data B) quantitative data
2) Classify the number of complaint letters received by the United States Postal Service in a given day as
qualitative data or quantitative data.
A) quantitative data B) qualitative data
3) Classify the number of seats in a movie theater as qualitative data or quantitative data.
A) quantitative data B) qualitative data
4) Classify the numbers on the shirts of a girlʹs soccer team as qualitative data or quantitative data.
A) qualitative data B) quantitative data
5) Quantitative variables classify individuals in a sample according to
A) Numerical measure B) Physical attribute
C) Personality characteristic D) Exhibited trait
4 Distinguish Between Discrete and Continuous Variables
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Classify the following random variable according to whether it is discrete or continuous.
The number of cups of coffee sold in a cafeteria during lunch
A) discrete B) continuous
2) Classify the following random variable according to whether it is discrete or continuous.
The height of a player on a basketball team
A) continuous B) discrete
3) Classify the following random variable according to whether it is discrete or continuous.
The blood pressure of a group of student the day before their final exam
A) continuous B) discrete
4) Classify the following random variable according to whether it is discrete or continuous.
The high temperature in degrees Fahrenheit on July 4th in Juneau, Alaska
A) continuous B) discrete
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, 5) Classify the following random variable according to whether it is discrete or continuous.
The number of goals scored in a soccer game
A) discrete B) continuous
6) Classify the following random variable according to whether it is discrete or continuous.
The speed of a car on a Los Angeles freeway during rush hour traffic
A) continuous B) discrete
7) Classify the following random variable according to whether it is discrete or continuous.
The number of phone calls to the attendance office of a high school on any given school day
A) discrete B) continuous
8) Classify the following random variable according to whether it is discrete or continuous.
The age of the oldest student in a statistics class
A) continuous B) discrete
9) Classify the following random variable according to whether it is discrete or continuous.
The number of pills in a container of vitamins
A) discrete B) continuous
10) The peak shopping time at home improvement store is between 8-11:00 am on Saturday mornings.
Management at the home improvement store randomly selected 150 customers last Saturday morning and
decided to observe their shopping habits. They recorded the number of items that a sapmle of the customers
purchased as well as the total time the customers spent in the store. Identify the types of variables recorded by
the home improvement store.
A) number of items - discrete; total time - continuous
B) number of items - continuous; total time - continuous
C) number of items - continuous; total time - discrete
D) number of items - discrete; total time - discrete
11) The number of violent crimes committed in a city on a given day in a random sample of 80 days is a
__________ random variable.
A) discrete B) continuous
12) Classify the following random variable: telephone area codes
A) Qualitative data B) Experimental data
C) Quantitative continuous data D) Quantitative discrete data
13) A student is asked to rate an instructorʹs ability to teach on a scale of poor - average - good - excellent . The
student is to fill in a corresponding circle on a bubble form. This is an example of collecting what type of data?
A) Qualitative B) Continuous C) Discrete D) Insightful
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